Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 48
Filtrar
1.
Zhonghua Yi Xue Za Zhi ; 102(40): 3160-3166, 2022 Nov 01.
Artigo em Chinês | MEDLINE | ID: mdl-36319170

RESUMO

Nucleoside/Nucleotide analogues (NAs) are widely used for the antiviral treatment of chronic hepatitis B (CHB), however, it is difficult to achieve serum hepatitis B surface antigen (HBsAg) loss with NAs therapy. In recent years, several prospective trails have reported that HBsAg loss (functional cure or clinical cure) also occurs in a small number of hepatitis B e antigen (HBeAg) negative CHB patients who discontinued long-term treatment with NAs. Accordingly, the "stop-to-cure" strategy is proposed. Although the mechanism has not been fully elucidated, the known factors related to serum HBsAg loss with NAs withdrawal include HBV genotype, duration of NAs treatment, serum HBsAg and HBV RNA levels at end-of-treatment, and ethnic differences. In the review, we discuss the best time to stop NAs therapy, the potential markers for predicting relapse after cessation of NAs and the possible mechanism of "stop-to-cure" in HBeAg-negative CHB patients, and propose some suggestions on the time of retreatment.


Assuntos
Antígenos de Superfície da Hepatite B , Hepatite B Crônica , Humanos , Antígenos E da Hepatite B , Estudos Prospectivos , Antivirais
2.
Zhonghua Yi Xue Za Zhi ; 102(9): 654-658, 2022 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-35249309

RESUMO

Objective: To analyze the changes of patellar tendon elasticity quantitatively of amateur marathon runners by shear wave elastography (SWE) in a half marathon. Methods: A total of 47 amateur marathon runners (31 males and 16 females, aged from 20 to 44 years) were enrolled as the marathon group, and divided into dominant side (47 patellar tendons) and non-dominant side (47 patellar tendons). Grey-scale ultrasound and SWE were performed on the bilateral patellar tendons before and after the half marathon within 2 h and after a period of 1 week. Thirty healthy volunteers (18 males and 12 females, aged from 22 to 39 years) were enrolled as the control group, the SWE-values derived from the patellar tendon were collected and analyzed. Multivariate logistic regression was performed to analyze the relationship between the changes of SWE-values and running age as well as weekly amount of running. Results: None of any runners showed knee pain and sports injury during the test. The dominant side had a higher SWE-values than non-dominant side in marathon group before running [(55.1±15.7) kPa vs (43.8±15.9) kPa, P<0.05]. The marathon group had higher SWE-values than the control group both in dominant side [(55.1±15.7) kPa vs (18.5±3.7) kPa] and non-dominant side [(43.8±15.9) kPa vs (17.4±3.2) kPa], respectively, before running (P<0.05). The SWE-values increased significantly both in dominant side [(80.2±23.2) kPa vs (55.1±15.7) kPa] and non-dominant side [(76.5±26.6) kPa vs (43.8±15.9) kPa] 2 h after running in marathon group. After a week, the SWE-values were not statistically different from those before running (P>0.05). Multivariate logistic regression showed that running age and weekly amount of running were related factors leading to the increase of SWE-values after running. Conclusions: The patellar tendon of amateur marathon runners has higher SWE-values. SWE can dynamically evaluate the changes of patellar tendon during exercise and is helpful for runners in scientific training and avoiding sports injury.


Assuntos
Técnicas de Imagem por Elasticidade , Ligamento Patelar , Adulto , Elasticidade , Feminino , Humanos , Masculino , Corrida de Maratona , Ligamento Patelar/diagnóstico por imagem , Ultrassonografia , Adulto Jovem
3.
Anaesthesia ; 76(9): 1224-1232, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34189735

RESUMO

Identification of high-risk patients admitted to intensive care with COVID-19 may inform management strategies. The objective of this meta-analysis was to determine factors associated with mortality among adults with COVID-19 admitted to intensive care by searching databases for studies published between 1 January 2020 and 6 December 2020. Observational studies of COVID-19 adults admitted to critical care were included. Studies of mixed cohorts and intensive care cohorts restricted to a specific patient sub-group were excluded. Dichotomous variables were reported with pooled OR and 95%CI, and continuous variables with pooled standardised mean difference (SMD) and 95%CI. Fifty-eight studies (44,305 patients) were included in the review. Increasing age (SMD 0.65, 95%CI 0.53-0.77); smoking (OR 1.40, 95%CI 1.03-1.90); hypertension (OR 1.54, 95%CI 1.29-1.85); diabetes (OR 1.41, 95%CI 1.22-1.63); cardiovascular disease (OR 1.91, 95%CI 1.52-2.38); respiratory disease (OR 1.75, 95%CI 1.33-2.31); renal disease (OR 2.39, 95%CI 1.68-3.40); and malignancy (OR 1.81, 95%CI 1.30-2.52) were associated with mortality. A higher sequential organ failure assessment score (SMD 0.86, 95%CI 0.63-1.10) and acute physiology and chronic health evaluation-2 score (SMD 0.89, 95%CI 0.65-1.13); a lower PaO2 :FI O2 (SMD -0.44, 95%CI -0.62 to -0.26) and the need for mechanical ventilation at admission (OR 2.53, 95%CI 1.90-3.37) were associated with mortality. Higher white cell counts (SMD 0.37, 95%CI 0.22-0.51); neutrophils (SMD 0.42, 95%CI 0.19-0.64); D-dimers (SMD 0.56, 95%CI 0.43-0.69); ferritin (SMD 0.32, 95%CI 0.19-0.45); lower platelet (SMD -0.22, 95%CI -0.35 to -0.10); and lymphocyte counts (SMD -0.37, 95%CI -0.54 to -0.19) were all associated with mortality. In conclusion, increasing age, pre-existing comorbidities, severity of illness based on validated scoring systems, and the host response to the disease were associated with mortality; while male sex and increasing BMI were not. These factors have prognostic relevance for patients admitted to intensive care with COVID-19.


Assuntos
COVID-19/mortalidade , Doença Crônica/mortalidade , Mortalidade Hospitalar , Unidades de Terapia Intensiva , Fatores Etários , Comorbidade , Cuidados Críticos , Humanos , Escores de Disfunção Orgânica , Fatores de Risco , SARS-CoV-2
4.
Zhonghua Gan Zang Bing Za Zhi ; 27(11): 910-912, 2019 Nov 20.
Artigo em Chinês | MEDLINE | ID: mdl-31941250

RESUMO

The 2019 European Association for the Study of the Liver (EASL) Clinical Practice Guidelines (hereinafter referred to as the EASL Guidelines) extracted the required evidence from detailed research materials, and rigorously graded and condensed the varying strengths of evidence into 32 recommendations and 14 statements (recommendations and reminders) for drug-induced Liver Injury (DILI). This guideline has important reference values for helping clinicians to further improve their understanding of DILI and the level of clinical diagnosis, treatment and prevention; however, there are still several issues worthy of further discussion.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Guias de Prática Clínica como Assunto , Doença Hepática Induzida por Substâncias e Drogas/diagnóstico , Doença Hepática Induzida por Substâncias e Drogas/terapia , China , Humanos , Sociedades Médicas
5.
Zhonghua Yu Fang Yi Xue Za Zhi ; 52(12): 1276-1280, 2018 Dec 06.
Artigo em Chinês | MEDLINE | ID: mdl-30522230

RESUMO

Objective: To study the effect of nutrition intervention on the body composition and blood glucose in newly diagnosed patients with type 2 diabetes mellitus complicated with overweight and obesity. Methods: A total of 84 newly diagnosed patients with type 2 diabetes mellitus complicated with overweight and obesity were selected from the department of endocrinology in China-Japan Friendship Hospital from April 2015 to December 2016. Basic information and body composition of these patients were collected and measured. Also the food frequency questionnaire (FFQ) was used to investigate the dietary status in the past month, and calculate the intake of energy, three major nutrients and dietary fiber. All patients received nutrition intervention by nutritionist for three months as requested by Diabetes guidelines. After 3-month intervention, blood glucose, body composition and dietary status were examined again. Relevant indicators of patients were compared before and after the intervention. All patients were divided into three groups according to the degree of body mass index (BMI)'s change: <5%, 5%-10% and >10%. The differences of body weight, muscle, body fat rate, visceral fat index and blood glucose level among three groups were quantified. Results: There were 53 male patients with age (41.5±8.9) years and HbA1c (7.5±0.4)%, and 31 female patients with age (40.1±8.5) years with HbA1c (7.6±0.5)%. The intake of energy, carbohydrate and fat of patients were significantly decreased (P<0.05) and dietary fiber was significantly increased (P<0.05) after nutrition intervention. The body weight, muscle mass, fat mass and visceral fat index were also significantly decreased (P<0.05). The average decrease of fat was about 2.8 kg accounting for 73.7% (2.8 kg/3.8 kg) of the total weight loss. The body fat rate decreased from (31.2±3.1)% to (28.8±3.2)% (P<0.05). The fasting blood glucose and postprandial blood glucose were both decreased significantly after intervention (P<0.05). Among three BMI decreased groups, there was no significant difference in body weight and muscle mass (P>0.05), but a significant difference in body fat rate and visceral fat index (P<0.05). The body fat rate, visceral fat index, fasting blood glucose and postprandial blood glucose had more decreases with the greater amount of weight loss (P<0.05). Conclusion: The three-month nutrition intervention could change the dietary habit and components of patients with type 2 diabetes mellitus by reducing the blood glucose, body fat rate and visceral fat index significantly. The degree of reduced BMI is positively related to the decrease of fasting blood glucose and postprandial blood glucose.


Assuntos
Diabetes Mellitus Tipo 2/dietoterapia , Sobrepeso/complicações , Adulto , Glicemia , Composição Corporal , China , Diabetes Mellitus Tipo 2/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/complicações , Resultado do Tratamento
6.
Zhonghua Gan Zang Bing Za Zhi ; 25(7): 481-484, 2017 Jul 20.
Artigo em Chinês | MEDLINE | ID: mdl-29055983

RESUMO

Chronic hepatitis B is a serious public health issue in China. The clinical management of hepatitis B is effective with the emergence of antiviral agents. The outcome of long-term therapy and nucleos(t)ide analogues stopping rules are currently unresolved issues and unmet needs. Thus, we need to pay more attention to clinical research to build large-sample and long-term follow-up cohorts and begin with the end in mind. We believe that the way to resolve the issues above will be found with the efforts of generations.


Assuntos
Hepatite B , Antivirais , China , Antígenos E da Hepatite B , Vírus da Hepatite B , Resultado do Tratamento
7.
Zhonghua Gan Zang Bing Za Zhi ; 25(7): 500-505, 2017 Jul 20.
Artigo em Chinês | MEDLINE | ID: mdl-29055987

RESUMO

The optimal clinical outcomes are the original intention and base to form the short-term, long-term and special goals of antiviral treatment in patients with hepatitis B virus (HBV) infection. The immediate indicators for assessment of antiviral clinical outcomes, which usually need prolonged follow-up, include the liver histopathological changes, the occurrence and severity of liver cirrhosis and hepatocellular carcinoma (HCC), mortality and survival rates, survival time and life quality, prevention rates of Mother-to-Child Transmission and HBV reinfection after liver transplantation, etc.


Assuntos
Hepatite B , Neoplasias Hepáticas , Antivirais , Carcinoma Hepatocelular , Vírus da Hepatite B , Humanos , Cirrose Hepática , Transplante de Fígado , Recidiva Local de Neoplasia , Resultado do Tratamento
8.
Zhonghua Yi Xue Za Zhi ; 96(34): 2722-2725, 2016 Sep 13.
Artigo em Chinês | MEDLINE | ID: mdl-27667105

RESUMO

Objective: The aim was to explore the strategy and clinical value of laparoscopic transection of median hepatic fissure (MHF) in difficult laparoscopic liver resections. Methods: First the MHF was located and marked, then the transection plane of the MHF was set. Next, the laparoscopic Multifuctional Operative Dissector (LPMOD) and the technique of curettage and aspiration were utilized to transect the liver beginning from the middle portion of the gallbladder fossa, in a caudal-to-cranial and anterior-to-posterior direction, until the clear exposure of the anterior surface of the intrahepatic inferior vena cava. Transection of the MHF was accurately achieved. Finally, dissection of the second and third porta hepatis were carefully performed and mobilization of the transected liver was achieved. This technique of laparoscopic transection of MHF was successfully performed in 13 patients in difficult laparoscopic liver resections. Results: Between April 2014 and August 2015, 13 patients received the technique of laparoscopic transection of MHF in difficult laparoscopic liver resections, including 10 cases of laparoscopic right hepatectomy, two cases of laparoscopic left hepatectomy and one case of associating liver partition and portal vein ligation for staged hepatectomy (ALPPS). The maximum size of the transected tumor was 15 centimeter. Duration of surgery was 240-430 min[Mean, 324.4±50.0]; the time for transection of the MHF was 40-118 min[mean, 66.4±22.7]. Blood loss was 200-2 000 ml[583.3±452.9]. The length of postoperative hospital stay was 6-25 days[mean, 13.2±5.2]. Seven patients received intraoperative transfusions. No postoperative intraabdominal bleeding, liver failure or other severe postoperative complications occurred. No perioperative death occurred. Conclusions: Application of laparoscopic transection of the MHF in difficult laparoscopic liver resections can help to clearly expose the second and third porta hepatis, especially in patients who have huge tumors and poor exposure for hepatic dissection. Moreover, precise location and transection of the MHF remains very important strategies of applying this technique.


Assuntos
Hepatectomia , Hepatopatias/cirurgia , Curetagem , Dissecação , Humanos , Laparoscopia , Tempo de Internação , Ligadura , Veia Porta , Complicações Pós-Operatórias , Período Pós-Operatório , Veia Cava Inferior
9.
Neuroscience ; 322: 78-93, 2016 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-26892297

RESUMO

The subplate (SP) plays important roles in developmental and functional events in the neocortex, such as thalamocortical and corticofugal projection, cortical oscillation generation and corticocortical connectivity. Although accumulated evidence indicates that SP interneurons are crucial for SP function, the molecular composition of SP interneurons as well as their developmental profile and distribution remain largely unclear. In this study, we systematically investigated dynamic development of SP thickness and chemical marker expression in SP interneurons in distinct cortical regions during the first postnatal month. We found that, although the relative area of the SP in the cerebral cortex significantly declined with postnatal development, the absolute thickness did not change markedly. We also found that somatostatin (SOM), the ionotropic serotonin receptor 3A (5HT3AR), and parvalbumin (PV) reliably identify three distinct non-overlapping subpopulations of SP interneurons. The SOM group, which represents ~30% of total SP interneurons, expresses neuronal nitric oxide synthase (nNOS) and calbindin (CB) and colocalizes entirely with neuropeptide Y (NPY). The 5HT3AR group, which accounts for ~60% of the total interneuronal population, expresses calretinin (CR) and GABA-A receptor subunit delta (GABAARδ). The PV group accounts for ~10% of total SP interneurons and coexpressed GABAARδ. Moreover, distinct interneuron subtypes show characteristic temporal and spatial distribution in the SP. nNOS(+) interneurons in the SP increase from the anterior motor cortex to posterior visual cortex, while CR(+) and CB(+) interneurons the opposite. Interestedly, the majority of GABAARδ(+) neurons in SP are non-GABAergic neurons in contrast to other cortical layers. These findings clarify and extend our understanding of SP interneurons in the developing cerebral cortex and will underpin further study of SP function.


Assuntos
Neurônios GABAérgicos/citologia , Neurônios GABAérgicos/fisiologia , Interneurônios/citologia , Interneurônios/fisiologia , Neocórtex/citologia , Neocórtex/crescimento & desenvolvimento , Animais , Animais Recém-Nascidos , Calbindinas/metabolismo , Contagem de Células , Técnicas de Introdução de Genes , Glutamato Descarboxilase/genética , Glutamato Descarboxilase/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Camundongos Transgênicos , Neocórtex/metabolismo , Neuropeptídeo Y/metabolismo , Óxido Nítrico Sintase Tipo I/metabolismo , Tamanho do Órgão , Parvalbuminas/metabolismo , Receptores de GABA-A/metabolismo , Receptores 5-HT3 de Serotonina/genética , Receptores 5-HT3 de Serotonina/metabolismo , Somatostatina/metabolismo
10.
Eur J Pain ; 18(2): 162-73, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23868758

RESUMO

BACKGROUND: In experimental early painful diabetic neuropathy, persistent hyperglycaemia induces dys-regulated sodium channel (Navs) expression in the dorsal root ganglion (DRG) and activates microglia in the spinal dorsal horn (SDH). However, information on diabetes-induced chronic neuropathic pain is limited. Therefore, we investigated abnormal Navs in the DRG and activated glial cells in the SDH of diabetic rats with chronic neuropathic pain. METHODS: Sixty-six rats were divided into diabetic and control groups: control rats (n = 18; 1 mL of normal saline via the right femoral vein) and diabetic rats [n = 48; 60 mg/kg streptozotocin (STZ) via the right femoral vein]. Hindpaw behavioural tests, Navs expression in the DRG, activation of glial cells in the SDH and the number of neurons in the SDH were measured at 1 and 2 weeks, and 1, 2, 3 and 6 months following saline and STZ administration. RESULTS: All diabetic rats exhibited hyperglycaemia from day 7 to 6 months. The diabetic rats decreased withdrawal threshold to mechanical stimuli but had blunted responses to thermal stimuli. Consistent up-regulation of Nav1.3 and down-regulation of Nav1.8 was observed. Microglial cells were activated early in the SDH and lasted for 6 months. A positive correlation between mechanical allodynia, Nav1.3 and microglial activation was observed. In addition, microglia activation in the SDH of STZ-induced diabetes was mediated, in part, by phosphorylation of p-38 mitogen-activated protein kinase. CONCLUSIONS: Diabetic rats showed hindpaw mechanical allodynia for 6 months. Persistent mechanical allodynia was positively associated with sustained increased activation of Nav1.3 and increased p38 phosphorylation in activated microglia.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Hiperalgesia/metabolismo , Microglia/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.3/metabolismo , Neuralgia/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Neuropatias Diabéticas/metabolismo , Modelos Animais de Doenças , Ativação Enzimática , Masculino , Fosforilação , Ratos , Ratos Sprague-Dawley , Regulação para Cima
11.
Exp Brain Res ; 227(4): 477-86, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23625076

RESUMO

While the process of hand preshaping during grasping has been studied for over a decade, there is relatively little information regarding the organization of digit contact timing (DCT). This dearth of information may be due to the assumption that DCT while grasping exhibits few regularities or to the difficulty in obtaining information through traditional movement recording techniques. In this study, we employed a novel technique to determine the time of digit contacts with the target object at a high precision rate in normal healthy participants. Our results indicate that, under our task conditions, subjects tend to employ a radial to ulnar pattern of DCT which may be modulated by the shape of the target object. Moreover, a number of parameters, such as the total contact time, the frequency of first contacts by the thumb and index fingers and the number of simultaneous contacts, are affected by the relative complexity of the target object. Our data support the notion that a great deal of information about the object's physical features is obtained during the early moments of the grasp.


Assuntos
Dedos/fisiologia , Força da Mão/fisiologia , Desempenho Psicomotor/fisiologia , Tempo de Reação/fisiologia , Feminino , Humanos , Masculino , Adulto Jovem
12.
Transplant Proc ; 43(7): 2678-82, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21911145

RESUMO

BACKGROUND: The use of dental implants in organ transplant patients remains controversial because of their altered wound healing and risk of serious infections. The aims of this study were to evaluate the long-term survival rate and related clincial parameters of dental implants among liver transplant patients on immunosuppressive medications. METHODS: We placed 45 implants in 13 liver transplant patients. All implants were sucessfully placed in the mandible or maxilla. The success rate, perimplant bone absorption (MBL), probing depth and Periotest values were measured at 3 months, as well as 1 and 3 years. RESULTS: At 3 years' follow-up, no implants were lost. MBL and Periotest values were within acceptable ranges without bleeding on probing or pathological probing depth. CONCLUSION: This series supports the use of dental implants in liver transplant patients who are stable under long-term immunosuppression.


Assuntos
Implantes Dentários , Transplante de Fígado , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Taxa de Sobrevida , Cicatrização
13.
J Dent Res ; 90(10): 1197-201, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21771797

RESUMO

The objectives of this study were to compare the survival time of the Hawley retainer (HR) and the clear overlay retainer (COR) over one-year follow-up and to analyze risk factors contributing to their breakage. In this randomized, controlled clinical trial, we assigned 120 adolescent patients to receive either the HR or the COR. All specific data on breakage dates, the reasons for breakage, and the broken parts of the retainers were recorded. A survival analysis was used to describe retainer survival over time. No significant differences were observed in survival times between the 2 groups for either the maxillary retainer (p = 0.254) or the mandibular retainer (p = 0.188). Both retainers tended to fracture, but the fracture locations were different. The findings indicate that clinicians should avoid increasing buccal root torque and reinforce the retainer base plates. Breakage rates may not influence the choice of retainer (Trial Registration number is ChiCTR-TRC-00000055).


Assuntos
Contenções Ortodônticas , Adolescente , Distribuição de Qui-Quadrado , Criança , Método Duplo-Cego , Falha de Equipamento , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Modelos de Riscos Proporcionais , Estudos Prospectivos , Estatísticas não Paramétricas
14.
Domest Anim Endocrinol ; 41(2): 57-66, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21600726

RESUMO

The aim of this study was to show a stimulatory role in ovarian follicle development by prolactin (PRL) in chicken hens. In experiment 1, anti-PRL antibodies were generated in hen plasma by intramuscular administrations of recombinant PRL antigen. Egg laying remained at levels lower (P < 0.05) in the PRL-immunized group than in the BSA-immunized group of hens, whereas development of incubation was depressed in the former but not the latter group. Throughout the experiment, plasma PRL concentrations were lower in the PRL-immunized hens than in non-incubating control hens; LH concentrations were similar between the PRL- and BSA-immunized hens until the end of the experiment when LH was lower in the BSA-immunized hens (P < 0.05). In experiment 2, anti-PRL receptor (PRLR) antibodies were raised in hens with the use of immunizations against recombinant PRLR extracellular domain. Immunization against PRLR initially increased the egg-laying rate when measured under the short photoperiod (12 h) but blocked the laying rate increase that occurred in the BSA-immunized control hens when the photoperiod was extended from 12 to 16 h. The development of incubation behavior was not affected by immunization against PRLR nor was plasma PRL or LH concentration. In experiment 3, when the egg-laying rate was depressed in PRL immunization hens, developmental speed of large white follicles was found to be slower than in the BSA-immunized control hens (P < 0.05). These results indicate that immunization against PRL slows down ovarian follicular development and reduces hen egg-laying performance, suggesting that PRL plays a stimulatory role in ovarian follicular development in chicken hens.


Assuntos
Galinhas/fisiologia , Folículo Ovariano/fisiologia , Oviposição/fisiologia , Prolactina/fisiologia , Receptores da Prolactina/fisiologia , Animais , Feminino , Hormônio Luteinizante/sangue , Hormônio Luteinizante/fisiologia , Progesterona/sangue , Progesterona/fisiologia , Prolactina/sangue
15.
Br Poult Sci ; 47(1): 88-94, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16546802

RESUMO

1. Three experiments were conducted to study the effects of leptin on weight gain and body composition in laying hens. 2. The effects of immunisation against chicken leptin on feed intake (FI), fat deposition and laying rate were observed in laying Guangdong yellow-feathered hens. Ten hens were inoculated with leptin immunogen on d 3, 31, 63 and 84, together with 10 control hens immunised with bovine serum albumin (BSA). In the 100-d experiment, immunisation against leptin increased blood anti-leptin antibody titres, slightly reduced plasma T3 concentrations, slightly decreased FI and increased live weight; however, laying rate was significantly depressed and abdominal fat mass was increased by the end of the 100-d experiment. 3. Passive immunisation of 50-d-old pullets with yolk extract containing anti-leptin antibody IgY significantly increased FI within 6 h of treatment compared with physiological saline treated controls. 4. In growing 70-d-old pullets, inoculation with 0.5 (group 1) or 1 (group 2) ml leptin immunogen on d 1 and 28 of the experiment slightly increased FI and significantly increased daily gain compared with BSA-immunised control pullets. Abdominal fat mass on d 49 increased from 48+/-4.5 g in controls to 66+/-3.5 and 80+/-3.1 g in groups 1 and 2, respectively. 5. It was suggested that immunisation against leptin mimicked loss of leptin bioactivity and might become a novel technique to stimulate fat growth in certain types of animal production.


Assuntos
Tecido Adiposo/metabolismo , Comportamento Alimentar/fisiologia , Imunização , Leptina/imunologia , Leptina/metabolismo , Oviposição/fisiologia , Aumento de Peso , Animais , Anticorpos/sangue , Antígenos/imunologia , Antígenos/metabolismo , Galinhas , Gema de Ovo , Comportamento Alimentar/efeitos dos fármacos , Feminino , Imunoglobulinas/metabolismo , Leptina/antagonistas & inibidores , Proteínas Recombinantes/imunologia
16.
Ann Biomed Eng ; 29(7): 595-606, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11501624

RESUMO

A cardiovascular parameter estimator to identify the systemic vascular parameters was developed using an extended Kalman filter (EKF) algorithm. Measurements from a ventricular assist device (VAD) and arterial pressure were used in the estimator. The systemic vascular parameters are important indices of heart condition. However, obtaining these parameters usually requires invasive measurements, which are difficult to obtain under most clinical environments. Including a VAD model into the estimator and using the signals from a VAD to identify the cardiovascular parameters for VAD patients would minimize the need for indwelling sensors. This paper illustrates the use of a Novacor left ventricular assist system (LVAS) model with a cardiovascular model in the estimator to identify the systemic vascular parameters: characteristic resistance, blood inertance at the aorta, systemic compliance, and systemic resistance. Performance of the estimator was evaluated using data from a computer simulation and from a mock circulatory system experiment. Robustness of the estimator to the available measurements was also described. The estimation results showed that the estimates converged with reasonable accuracy in a limited time when the LVAS pump volume and arterial pressure were used as measurements. These parameter estimates can provide additional diagnostic information for patient and device monitoring and can be used for future VAD control development.


Assuntos
Coração Auxiliar , Modelos Cardiovasculares , Algoritmos , Engenharia Biomédica , Simulação por Computador , Circulação Coronária/fisiologia , Humanos
17.
ASAIO J ; 47(3): 293-301, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11374776

RESUMO

A mathematical model describing the pressure-volume relationship of the Novacor left ventricular assist system (LVAS) was developed. The model consists of lumped resistance, capacitance, and inductance elements with one time varying capacitor to estimate the cyclic pressure generation of the pump using pump volume measurement. The ejection and filling portions of the pump cycle were modeled with two separate functions. The corresponding model parameters were estimated by least squares fit to experimental data obtained in the laboratory. Pressure and volume waveforms obtained from the model were compared with data obtained from laboratory tests and from patients. It performed well in simulating pump operation throughout the entire cycle. This model can be used for the evaluation of LVAS performance, for on-line estimation of an LVAS patient's cardiovascular parameters, for pump controller development, and as a tool for engineer training.


Assuntos
Coração Auxiliar , Hemodinâmica , Modelos Cardiovasculares , Fluxo Pulsátil , Humanos , Desenho de Prótese
18.
Hu Li Yan Jiu ; 9(3): 344-53, 2001 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-17953078

RESUMO

Infertile women suffer chronic stress, which may negatively impact their parenting relationships if they later succeed in bearing children. The purpose of this study was to explore the parenting stress of mothers attending assisted an reproductive program and to compare it with the parenting stress of mothers with natural pregnancies. A purposive sampling method was used to recruit 54 mothers attending an In Vitro Fertilization/Embryo Transfer and Tubal Embryo Transfer program at an infertility center in central Taiwan. Three instruments were used to collect data: the Demographic Data Form, Parenting Stress Index-Short Form and Family Adaptation Partnership Growth Affective Relation Index. The data were analyzed by descriptive and inferential statistical methods. (1) The results indicated that the highest average score in parenting stress for mothers receiving reproductive technology was for "parental distress". These results revealed that the main source of parenting stress was their parental role. (2) Family function varied significantly with parenting stress. (3) Parenting stress was significantly greater in mothers with natural pregnancy than in mothers attending the assisted reproductive program. Recommendations for clinical application and future research are also made. The implications of the study may be used to assist infertile women in coping with parenting roles. Furthermore, a qualitative study is suggested to understand the factors which cause parenting stress.


Assuntos
Poder Familiar/psicologia , Técnicas de Reprodução Assistida , Estresse Psicológico , Feminino , Humanos , Gravidez
19.
Heredity (Edinb) ; 83 ( Pt 1): 39-45, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10447701

RESUMO

A 'stepwise chromosome evolution model' is proposed to elaborate the two stages of the sex chromosome evolution of Drosophila albomicans. To explain the occurrence of both a 3-X and a 3-Y in this species it is proposed that these chromosomes evolved sequentially. The selection forces acting in the two stages are different. The genic composition in the first fused sex chromosome of D. albomicans was supposed to be selectively superior to the primitive unfused chromosomes, thus the fused chromosome could overcome the meiotic structural incompatibility and be maintained in the population during the first stage. When the second fusion occurred, the newly fused sex chromosome was preferentially selected, as it could provide a meiotic pairing partner for the first fusion. The fused sex chromosomes were eventually fixed in the population. Based on this model, we tried to determine which fused chromosome, 3-X or 3-Y, established first. The karyotyping result of four experimental hybrid populations showed that the fused 3-X, as opposed to 3-Y, chromosome has higher fitness values. However, without the coexistence of 3-X, 3-Y is excluded rapidly. Therefore, 3-X is likely to be the first fused chromosome in the stepwise chromosome evolution model. The formation and fixation of the fused 3-Y chromosome occurred subsequently.


Assuntos
Drosophila/citologia , Drosophila/genética , Evolução Molecular , Cromossomos Sexuais , Animais , Quimera , Aberrações Cromossômicas , Feminino , Cariotipagem , Masculino
20.
Biochemistry ; 38(5): 1659-68, 1999 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-9931034

RESUMO

Organized polymeric assemblies that incorporate bioactive sequences and structures are finding important applications for the study of protein structure-function relationships. We have recently described a heteropolymeric peptide-amphiphile system that forms organized structures in solution and on surfaces. While the overall three-dimensional features of peptide-amphiphiles have been studied previously, the precise environment of specific residues, particularly those within biologically active regions, have not been examined in detail. In the present study, we have used heteronuclear single quantum coherence (HSQC) and inverse-detected 1H-15N NMR spectroscopy to examine the structure and dynamics of a peptide and peptide-amphiphile that incorporate the alpha1(IV)1263-1277 ([IV-H1]) amino acid sequence from type IV collagen. Three variants of the sequence (Gly-Pro-Hyp)4-[IV-H1]-(Gly-Pro-Hyp)4 were constructed with a single 15N-labeled Gly placed in the middle of the N-terminal (Gly-Pro-Hyp)4 region (residue Gly7), in the middle of the [IV-H1] sequence (residue Gly19), or in the middle of the C-terminal (Gly-Pro-Hyp)4 region (residue Gly34). These peptides were also N-terminally acylated with hexanoic acid to create an analogous series of 15N-labeled peptide-amphiphiles. HSQC spectra indicated that both the peptide and the peptide-amphiphile were in triple-helical conformation at low temperature, supporting prior circular dichroism (CD) spectroscopic results. The intensities of the triple-helical cross-peaks were stronger for the peptide-amphiphile, consistent with an enhanced triple-helical thermal stability within the peptide-amphiphile construct compared to that of the peptide alone. Relative relaxation values for the peptide-amphiphile monomeric and trimeric species were consistent with those reported previously for other triple-helical peptides. Relaxation measurements indicated that the triple-helical [IV-H1] region did not appear to be dramatically more flexible than the Gly-Pro-Hyp regions. The angle between Gly N-H bonds and the helix dyad axis, determined from the relaxation data, was within the range expected for triple helices. Overall, the peptide headgroup of the C6-(Gly-Pro-Hyp)4-[IV-H1]-(Gly-Pro-Hyp)4 peptide-amphiphile appears to form a continuous triple helix that behaves similarly, in a dynamic sense, to a triple-helical peptide. The enhanced thermal stability of the peptide-amphiphile compared to the analogous triple-helical peptide, along with the multitude of organized structures formed by lipidlike compounds, suggest that peptide-amphiphiles could be utilized as targeted liposomes, sensors, receptors, or enzymes.


Assuntos
Peptídeos/química , Tensoativos/química , Sequência de Aminoácidos , Colágeno/química , Modelos Químicos , Dados de Sequência Molecular , Isótopos de Nitrogênio , Ressonância Magnética Nuclear Biomolecular , Oligopeptídeos/síntese química , Oligopeptídeos/química , Peptídeos/síntese química , Conformação Proteica , Estrutura Secundária de Proteína , Relação Estrutura-Atividade , Tensoativos/síntese química , Termodinâmica
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...